Electro-active intraocular lenses

ABSTRACT

An intraocular lens system is presented that comprises an electro-active lens comprising multiple independently controllable zones or pixels, and a controller capable of being remotely programmed.

RELATED PATENTS AND APPLICATIONS

This application is a continuation under 35 U.S.C. §120 of U.S.application Ser. No. 11/261,035, now U.S. Pat. No. 8,778,022, which wasfiled on Oct. 2, 2005, and which in turn claims the benefit under 35U.S.C. §119(e) of: U.S. application No. 60/692,270, filed Jun. 21, 2005;U.S. application No. 60/687,341, filed Jun. 6, 2005; U.S. applicationNo. 60/687,342, filed Jun. 6, 2005; U.S. application No. 60/685,407,filed May 31, 2005; U.S. application No. 60/679,241, filed May 10, 2005;U.S. application No. 60/674,702, filed Apr. 26, 2005; U.S. applicationNo. 60/673,758, filed Apr. 22, 2005; U.S. application No. 60/669,403,filed Apr. 8, 2005; U.S. application No. 60/667,094, filed Apr. 1, 2005;U.S. application No. 60/666,167, filed Mar. 30, 2005; U.S. applicationNo. 60/661,925, filed Mar. 16, 2005; U.S. application No. 60/659,431,filed Mar. 9, 2005; U.S. application No. 60/636,490, filed Dec. 17,2004; U.S. application No. 60/623,947, filed Nov. 2, 2004; and U.S.application No. 60/623,946, filed Nov. 2, 2004, each of which isincorporated herein by reference in its entirety.

The following applications, provisional applications, and patents areincorporated by reference in their entirety: U.S. application Ser. No.11/232,551 filed Sep. 22, 2005; U.S. Pat. No. 6,918,670 issued Jul. 19,2005; U.S. application Ser. No. 11/183,454 filed Jul. 18, 2005; U.S.Provisional Application No. 60/692,270 filed Jul. 21, 2005; U.S.Provisional Application No. 60/687,342 filed Jun. 6, 2005; U.S.Provisional Application No. 60/687,341 filed Jun. 6, 2005; U.S.Provisional Application No. 60/685,407 filed May 31, 2005; U.S.Provisional Application No. 60/679,241 filed May 10, 2005; U.S.Provisional Application No. 60/674,702 filed Apr. 26, 2005; U.S.Provisional Application No. 60/673,758 filed Apr. 22, 2005; U.S.application Ser. No. 11/109,360 filed Apr. 19, 2005; U.S. ProvisionalApplication No. 60/669,403 filed Apr. 8, 2005; U.S. ProvisionalApplication No. 60/667,094 filed Apr. 1, 2005; U.S. ProvisionalApplication No. 60/666,167 filed Mar. 30, 2005; U.S. Pat. No. 6,871,951issued Mar. 29, 2005; U.S. application Ser. No. 11/091,104 filed Mar.28, 2005; U.S. Provisional Application No. 60/661,925 filed Mar. 16,2005; U.S. Provisional Application No. 60/659,431 filed Mar. 9, 2005;U.S. application Ser. No. 11/063,323 filed Feb. 22, 2005; U.S. Pat. No.6,857,741 issued Feb. 22, 2005; U.S. Pat. No. 6,851,805 issued Feb. 8,2005; U.S. application Ser. No. 11/036,501 filed Jan. 14, 2005; U.S.application Ser. No. 11/030,690 filed Jan. 6, 2005; U.S. applicationSer. No. 10/996,781 filed Nov. 24, 2004; U.S. Provisional ApplicationNo. 60/623,947 filed Nov. 2, 2004; U.S. application Ser. No. 10/924,619filed Aug. 24, 2004; U.S. application Ser. No. 10/918,496 filed Aug. 13,2004; U.S. application Ser. No. 10/863,949 filed Jun. 9, 2004; U.S. Pat.No. 6,733,130 issued May 11, 2004; U.S. application Ser. No. 10/772,917filed Feb. 5, 2004; U.S. Pat. No. 6,619,799 issued Sep. 16, 2003; U.S.application Ser. No. 10/664,112 filed Aug. 20, 2003; U.S. applicationSer. No. 10/627,828 filed Jul. 25, 2003; U.S. application Ser. No.10/387,143 filed Mar. 12, 2003; U.S. Pat. No. 6,517,203 issued Feb. 11,2003; U.S. Pat. No. 6,491,391 issue Dec. 10, 2002; U.S. Pat. No.6,491,394 issued Dec. 10, 2002; and U.S. application Ser. No. 10/263,707filed Oct. 4, 2002.

BACKGROUND

The present invention relates to field of Intraocular Lenses (IOLs). Inparticular, the present invention relates to Intraocular Lenses whereinan electro-active element provides at least a portion of the IOL'srefractive power, or prismatic power, or at least a portion of thetinting.

Intraocular lenses (IOLs) are typically permanent, plastic lenses thatare surgically implanted inside of the eyeball to replace or supplementthe eye's natural crystalline lens. They have been used in the UnitedStates since the late 1960s to restore vision to cataract patients, andmore recently are being used in several types of refractive eye surgery.

The natural crystalline lens is critical component of the complexoptical system of the eye. The crystalline lens provides about 17diopters of the total 60 diopters of the refractive power of a healthyeye. Further, a healthy crystalline lens provides adjustable focusingwhen deformed by the muscular ciliary body that circumferentiallysurrounds the crystalline lens. As the eye ages, the flexibility of thecrystalline lens decreases and this adjustable focusing is diminished.Thus, this critical crystalline lens almost invariably loses flexibilitywith age, and often loses transparency with age due to cataracts orother diseases.

Most intraocular lenses used in cataract surgery may be folded andinserted through the same tiny opening that was used to remove thenatural crystalline lens. Once in the eye, the lens may unfold to itsfull size. The opening in the eye is so small that it heals itselfquickly without stitches. The intraocular lenses may be made of inertmaterials that do not trigger rejection responses by the body.

In most cases, IOLs are permanent. They rarely need replacement, exceptin the instances where the measurements of the eye prior to surgery havenot accurately determined the required focusing power of the IOL. Also,the surgery itself may change the optical characteristics of the eye. Inmost cases, the intraocular lenses implanted during cataract surgery aremonofocal lenses, and the optical power of the IOL is selected such thatthe power of the eye is set for distance vision. Therefore, in mostcases the patient will still require reading glasses after surgery.Intraocular lens implants may be static multifocal lenses, which attemptto function more like the eye's natural lens by providing clear visionat a distance and reasonable focus for a range of near distances, forpatients with presbyopia. Not all patients are good candidates for themultifocal lens; however, those who can use the lens are some whatpleased with the results.

More recently, accommodative IOLs have been introduced. Theseaccommodative IOLs actually change focus by movement (physicallydeforming and/or translating within the orbit of the eye) as themuscular ciliary body reacts to an accommodative stimulus from thebrain, similar to the way the natural crystalline lens focuses. Whilethese offer promise, accommodative IOLs still have not been perfected.In spite of these limited successes, the multifocal IOL and presentaccommodative IOLs still have a substantial decrease in performance whencompared to a healthy natural crystalline lens.

Another ocular lens that holds promise for correcting presbyopia is theSmall Diameter Corneal Inlay (SDCI). The Small Diameter Corneal Inlay(SDCI) is a prescription lens that is inserted into the corneal tissueto create an effect similar to a bifocal contact lens. Corneal Inlays(SDCI) are early in their development and it is still too early tounderstand how well they will function and also how effective they willbecome.

While all these emerging surgical procedures have their merits, they allhave a substantial decrease in performance when compared to a younghealthy natural crystalline lens. The present invention addresses theseshortcomings by providing an intraocular lens that behaves in a mannersimilar to the natural crystalline lens.

SUMMARY

An illustrative aspect of the invention provides an intraocular lenssystem comprising an electro-active lens comprising multipleindependently controllable zones or pixels, and a controller capable ofbeing remotely programmed.

Other aspects of the invention will become apparent from the followingdescriptions taken in conjunction with the following drawings, althoughvariations and modifications may be effected without departing from thespirit and scope of the novel concepts of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be more fully understood by reading thefollowing detailed description together with the accompanying drawings,in which like reference indicators are used to designate like elements.

FIG. 1 displays the major anatomical components of a human eye.

FIG. 2A displays a front view of an intraocular lens embodiment with anelectro-active lens and piezoelectric material as a power supply.

FIG. 2B displays a side view of an intraocular lens embodiment with anelectro-active lens and piezoelectric material as a power supply.

FIG. 3A displays a front view of an intraocular lens embodiment with adiffractive electro-active lens and a rechargeable battery ring.

FIG. 3B displays aside view of an intraocular lens embodiment with adiffractive electro-active lens and a rechargeable battery ring.

FIG. 4A displays a front view of an intraocular lens embodiment with apixelated electro-active lens and a rechargeable battery ring.

FIG. 4B displays amide view of an intraocular lens embodiment with apixelated electro-active lens and a rechargeable battery ring.

FIG. 5 displays an external power supply embodiment with inductivecharging elements inside of a pillow.

FIG. 6 displays an intraocular lens embodiment with an electro-activelens and a control chip with an antenna for use with a wirelessprogramming unit.

FIG. 7A is an image of an healthy retina illustrating the location ofthe macula and the fovea on the retina.

FIG. 7B illustrates an area of the macula that has been damaged by “wet”macular degeneration.

FIG. 7C illustrates an area of the macula that has been damaged by “dry”macular degeneration.

FIG. 8 illustrates the various manifestations of diabetic retinopathy.

FIG. 9 illustrates the stacking of two prismatic lenses with linearelectrodes to produce any combination of vertical and horizontaldisplacement of an image on the retina

FIG. 10 illustrates an electro-active IOL in optical communication witha non-electro-active accommodative IOL.

DETAILED DESCRIPTION

Hereinafter, various embodiments of the invention will be described. Asused herein, any term in the singular may be interpreted in the plural,and alternately, any term in the plural may be interpreted to be in thesingular.

Electro-active materials comprise optical properties that may be variedby electrical control. For example, transmission of light may becontrolled to produce tinting or a sunglass effect. Further, the indexof refraction may be electrically controlled to produce focusing and orprismatic effects. One class of electro-active material is liquidcrystals. Liquid crystals comprise a state of aggregation that isintermediate between the crystalline solid and the amorphous liquid. Theproperties of liquid crystals may be controlled electrically, thermally,or chemically. Many liquid crystals are composed of rod-like molecules,and classified broadly as: nematic, cholesteric, and smectic.

There are several characteristics of electro-active materials which areuseful in IOLs. First, the optical characteristics may be generated bythin layers (rather than by the curvature of conventional lenses whichmay require thick lenses). These thin layers may be placed in locationswhere it may be difficult to place conventional lenses, for example inthe anterior chamber of the eye (between the iris and the crystallinelens). In addition, it is possible to stack (place in series optically)the electro-active layers in such a manner as to get an additive effectfor the overall optical power created, including prism, conventionalrefractive error, or higher order aberration correction, in a thinstructure that may be placed in either the anterior or the posteriorchamber of the eye.

Second, the optical characteristics may be actively controlled. Forexample, an electro-active lens may designed to become darker (moretinted, and transmit less light) under bright light conditions. Thistinting may be generated automatically by measuring the brightnessusing, for example, a photodiode or solar cell. Alternately, the tintingmay be controlled by the decisions of the user by way of a remotecontrol.

Similarly, the focus of an electro-active lens may be controlledelectrically. The focus may be controlled automatically using, forexample, a range finder, or a tilt meter, or triangulation based on thedirection of both eyes, the forces exerted on the lens by the muscles ofthe eye. Alternately, the focus may be controlled by the decisions ofthe user by way of a remote control.

Third, electrical control creates the potential for correcting complexand high order visual defects. Conventional intraocular lenses arelimited to addressing certain visual defects for various manufacturingreasons. However, an electro-active lens with a large number ofindividually addressable controlled small elements (for example, anarray of very small pixels) may address very complex and high ordervisual defects. Further, the control may be simplified by creatingindividually addressable elements in arbitrary configurations, such as aseries of concentric circles, or a series of approximately concentricellipsis, or whatever customized configuration efficiently corrects thevisual defect. The design, manufacture, and control of an array of smallpixels has similarities with the manufacture of Liquid Crystal Displays(LCDs). Correction of complex visual defects such as higher orderaberrations of the eye creates the possibility of “superhuman” visualacuity, wherein the vision is not limited by the lenses (eitherbiological or corrective), but rather is limited by the inherent anatomyand physics of the photoreceptor cells in the retina. 20/10 vision orbetter is possible even before additional magnification is considered.Further, it is possible for an electro-active lens to act as a telescopeor as a microscope.

Fourth, electrical control creates the potential for changing theoptical characteristics of the electro-active IOL as desired. Forexample, the desired optical characteristics may be determined after theIOL is surgically implanted in order to compensate for any changes thatoccur during surgery, or for that matter an error in calculating orestimating the post surgery refractive error. Similarly, the opticalcharacteristics of the IOL may be varied over time to compensate forchanges in the user's eye. For example, if the user has a degenerativedisease that affects a portion of the retina, then it is possible toremotely cause the implanted electro-active IOL to create prismaticpower or even change its prismatic power in order to shift the image toa portion of the retina that is undamaged. By way of example only, eachmonth (or as needed) the image may be shifted to the remaining undamagedportion of the retina with the highest concentration of receptor cells.This change can be accomplished post-surgically and remotely (meaningwithout additional surgery).

Fifth, electrical control creates the potential for the user toautomatically or instinctively control the focus. For example,contractions of the muscular ciliary body can be measured by anpiezoelectric element (as a strain gauge), and these contractions canthen be used as a control input to electrically adjust the focus of theIOL, similar to the way the ciliary body would focus the naturalcrystalline lens by physical deformation. Additionally, in theory, thefocus could be controlled by electrical signals directly from the brain.Recent development with artificial limbs use this technique.

Sixth, electrical control creates the potential to shift the field ofview, and thus compensate for diseases that prevent the eyeball frommoving. Nervous signals to diseased muscles (that can no longer move theeye) may be intercepted, translated, and used to electrically shift thefield of view.

Seventh, there are many types of electro-active element configurations.These configurations include: pixelated (typically a two dimensionalarray of pixels similar to a liquid crystal monitor on a computer),rotationally symmetric pixelated (for example, a set of concentriccircles), and diffractive. Electro-active individually addressablepixelated diffractive lenses may use concentric ring shaped electrodesto product the diffractive lens power with varying index of refractionwithout physically machining, molding or etching diffractive elementsinto the surface of the lens.

The electro-active element may be used in combination with aconventional lens, wherein the conventional lens may provide a baserefractive power. The electro-active element may be used in combinationwith a diffractive lens having a machined, molded, or etched surface orgeometry. The electro-active element may be used in combination with asecond electro-active element, wherein each may perform a differentfunction. For example, the first electro-active element may providefocus, and the second may provide tinting or may serve as anelectrically controlled aperture, or the second could cause a prismaticshift of the image to the healthy area of a retina of a deceased eye.

Eighth, as discussed above, it is possible to electrically replace manyof the optical functions of a natural eye: tinting may replace oraugment the light reducing effect of the contraction of the iris,focusing may replace the natural deformation of the crystalline lens,focusing and prismatic shifting may replace movement of the eyeball, andso forth. Among other factors, the present invention addresses:positioning the IOL, energy storage, energy recharging, powergeneration, control, steering of the line of site to a targeted regionof the retina altering the refractive power of the eye, augmenting orreplacing the accommodative power of the crystalline lens, remote tuningpost surgery of the electro-active IOL. Tuning comprises altering thepower of the IOL and/or altering the location of the focus on the retinaof the IOL.

FIG. 1 displays the major anatomical components of a human eye. Themajor anatomical components are: conjunctiva 110, ciliary body 112, iris114, aqueous humor 116, pupil 118, anterior chamber 120, crystallinelens 122, cornea 124, extraocular muscles 126, sclera 128, chorid 130,macula lutea 132, optic nerve 134, retina 136, and vitreous humor 138.Although a human eye is described, this invention is also applicable tonon-human eyes such as horses or dogs.

As background, the optical components of the eye will be described indetail. Light entering the eye first enters the cornea 124. The cornea124 is transparent and provides about 40 diopters of the approximately60 diopters total refractive power of the eye. Light then passes throughthe pupil 118. The pupil 118 is an aperture, and is variable in diameterfrom 1 mm to at least 8 mm. This gives an aperture range in excess off20-f2.5, and a ratio of 32:1 for the amount of light permitted to enterthe eye. The iris 114 serves as an adjustable diaphragm creating a pupil118. The light then passes through the crystalline lens 122. Thecrystalline lens 122 is a transparent, encapsulated, biconvex body whichis attached circumferentially to the ciliary body 112. The crystallinelens 122 contributes about 17 diopters to the total refractive power ofa relaxed eye. The refractive power of the crystalline lens 122 may bealtered by contractions of the ciliary muscles in the ciliary body 112,which deform the crystalline lens 122 and alter its refractive power.The light then passes through the vitreous humor 138 and finallycontacts the retina 136. The retina 136 is the sensory neural layer ofthe eyeball and may be considered as an outgrowth of the brain, and isconnected to the brain through the optic nerve 134. Near the center ofthe retina 136, the macula lutea 132 contains a central region ofhighest visual sensitivity called the fovea centralis or foveola (seeFIG. 7) with a diameter of approximately 0.4 mm where the visualresolution is the highest. The small diameter of the foveola is one ofthe reasons why the optical axes must be directed with great accuracy toachieve good vision.

Thus, the human eye has an adjustable diaphragm (iris 114) and anadjustable refractive power (due to the ciliary body 112 deforming thecrystalline lens 124).

An IOL can be placed in one of three locations: in the anterior chamber120, which is between the cornea 124 and the iris 114; or in theposterior chamber (not shown) which is between the iris 114 and thecrystalline lens 122; or as a replacement for the crystalline lens 122.

Generally, if the crystalline lens is diseased or damaged, then an IOLmay be used to replace the crystalline lens. This IOL replacement forthe crystalline lens may be accommodative, or non-accomodative.Replacing the crystalline lens allows the IOL to be convenientlypositioned inside of a clear bag-like capsule that previously held thenatural crystalline lens, and also allows the possibility of retainingsome variable focus capability through interaction with the muscularciliary body which circumferentially surrounds the clear bag-likecapsule. In other cases, the IOL is placed extra capsulary (without thebag-like capsule).

However, if the crystalline lens is still functional, then it may bepreferable to leave the crystalline lens undisturbed and to place theelectro-active IOL into either the posterior chamber or the anteriorchamber 120 of the eye, or into the corneal tissue similar to the SmallDiameter Corneal Inlay (SDCI) discussed above. In these embodiments, theelectro-active IOL could, by way of example only, provide optical powerto correct for conventional refractive errors, correct fornon-conventional refractive errors, create a prismatic image shiftingeffect that moves the location of focus to a healthier area of theretina, and add a tint, as opposed to replacing the optical power of theotherwise healthy crystalline lens.

Conventional refractive error is defined as one or more of: myopia,hyperopia, pesbyopia, and regular astigmatism. Non-conventional (orhigher order) refractive errors are defined as all other refractiveerrors or aberrations which are not conventional refractive error.

In many cases, the electro-active IOL may be used during cataractsurgery when the existing crystalline lens is defective. In this case,the electro-active IOL will actually replace the removed defectiveexisting crystalline lens, and may provide a range of electro-activeoptical correction including conventional and/or non-conventionalrefractive errors, as well as provide refractive power to make up forthe lost optical power resulting from the removal of the crystallinelens. In addition, the electro-active IOL can provide for the ability toaccommodate without any movement, translation or change in its surfacegeometry. This is accomplished by localized programmed changes in theindex of refraction of the electro-active IOL.

The most common and advanced cataract surgery technique isphacoemulsification or “phaco.” The surgeon first makes a small incisionat the edge of the cornea and then creates an opening in the membranethat surrounds the cataract-damaged lens. This thin membrane is calledthe capsule. Next, a small ultrasonic probe is inserted through theopening in the cornea and capsule. The probe's vibrating tip breaks upor “emulsifies” the cloudy lens into tiny fragments that are suctionedout of the capsule by an attachment on the probe tip. After the lens iscompletely removed, the probe is withdrawn leaving only the clear (nowempty) bag-like capsule, which may act as support for the intraocularlens (IOL).

Phacoemulsification allows cataract surgery to be performed through avery small incision in the cornea. Stitches are seldom needed to closethis tiny entry, which means that there is less discomfort and quickerrecovery of vision than with other surgical techniques. Small incisionsgenerally do not change the curvature of the cornea (unlike largerincisions that were required with older surgical techniques). Smallincisions for more rapid rehabilitation of vision and possibly lessdependence on glasses for good distance vision.

After removal of the cataract-damaged lens, an artificial intraocularlens (IOL) may be implanted. The IOL may be produced from soft acrylicor solid medical-grade silicone. IOLs may be folded so they can beimplanted with a small injector, which uses the same incision throughwhich the phaco probe was inserted at the beginning of the procedure. Asthe IOL is implanted, it may be allowed to unfold and anchor itselfbehind the eye's pupil over the remaining clear capsule. The IOL(s) tobe implanted may be selected based on power calculations made beforesurgery. In the case of the present invention, the electro-active IOLmay also be selected based on the range of electro-active correctionrequired, the type of any other ocular disease being treated, and anyspecial needs of the patient.

In most cases, the electro-active element would contribute typically+2.5 Diopters, +2.75 Diopters, +3.0 Diopters, or +3.25 Diopters ofoptical power. The base lens portion (which the electro-active elementis in optical communication) which would contribute most, if not all, ofthe approximately 17 Diopters normally provided by the crystalline lens,would be measured and selected prior to surgery. However, unlike aconventional IOL, an electro-active IOL allows for remote tuning of itsoptical power (for example, in case the calculations made prior tosurgery are not optimum after surgery).

FIGS. 2A and 2B illustrate an IOL assembly 200 according to anembodiment of the invention. FIG. 2A displays a front view of the IOLassembly, which includes an electro-active lens element 218 powered by athin, annular charge storage capacitor 216 arranged around the perimeterof the electro-active lens element 218. The charge storage capacitor 216is charged by a piezoelectric film 212. The piezoelectric film 212generates this charge as a result of mechanical forces applied by theciliary body (not shown). The piezoelectric film 212 is attached to theciliary body by a ciliary body attachment tab 210.

The ciliary body expands and contracts as the eye attempts to focus fromnear to far and from far to near. The ciliary body movement may producetension and/or compression of the piezoelectric film 212 which produceselectricity. The electricity may be transferred through charging leads220 and used to charge the charge storage capacitor 216 (or arechargeable battery). The charge storage capacitor 216 may power theelectro-active lens element 218 and any related control circuitry (notshown). Typically the electro-active lens element 218 requiresapproximately 1.0 to 5.0 volts, with a preferred range of 1.5 to 2.5volts. These relatively low voltages decrease the risk involved withsurgical placement of electrical devices.

The electrical characteristics of the piezoelectric film 212 undertension or compression may be used as a gauge to determine the desiredviewing distance, and may be used to focus the electro-active lens.Thus, it is possible for the user to instinctively and automaticallycontrol the focus of the electro-active IOL 200 using the muscularciliary body. The contractions of the muscular ciliary body previouslyfocused the subject's crystalline lens by physically deforming it. Usingthe electro-active IOL 200 the instinctive and automatic contractions ofthe muscular ciliary body will change the electrical characteristics ofthe piezoelectric film 212, and these electrical changes may bemonitored by a processor disposed, for example, on a chip (not shown)and used to electrically, variably focus the electro-active IOL 200.Alternatively, the piezoelectric film 212 may be used solely as a gaugefor focusing, in which case, the electro-active IOL 200 would beprovided with a different source of power.

In some embodiments, the piezoelectric film may be attachedcircumferentially to the ciliary body by multiple attachment tabs (morethan two) in order to take advantage of the natural circumferentialcontraction and expansion of the surrounding ciliary body.

One or more lens anchors 214 may be used to stabilize the electro-activelens in the desired location. For example, a lens anchor 214 may be usedto center the electro-active lens inside of the capsule or “bag” ormembrane which formerly contained the natural crystalline lens (creatingan intracapsular IOL). Alternately, the lens anchor 214 may be attachedto the ciliary muscle directly, and thus be outside of the capsule(creating an extracapsular IOL).

Multiple lens anchors 214 may be used. For example, 3 or 4 lens anchors214 may be used. The lens anchors 214 may have different shapes,customized to the specific application.

An optional base lens 252 may provide a base refractive power using aconventional lens configuration, and may be equivalent in refractivepower to the crystalline lens when no accommodation is needed. The baselens 252 may also serve as a means of encapsulating the electro-activeelement in a hermetically sealed enclosure that consists of abiocompatible material similar to those materials currently used to makeIOLs, by way of example only, soft acrylic or solid medical-gradesilicone.

FIG. 2B displays a side view of an intraocular lens embodiment with anelectro-active lens and piezoelectric material as a power supply.Specifically, FIG. 2B illustrates the optional base lens 252 which maysurround the electro-active lens element 218 and which may provide afixed or base refractive power. In a particular embodiment, the fixed orbase refractive power may be adapted to focus the eye at near distanceswhen the electro-active element is inactive. In another embodiment, thefixed or base lens may be adapted to focus the eye at far distances whenthe electro-active element is inactive. The optional base lens 252 mayhave multiple focal points, and/or may be tinted.

Other sources of power may include: solar cells, inductive charging,conductive charging, laser, thermo-electric, and harnessing themechanical energy from blinking. The capacitor 216 (or optionally, abattery) may be recharged inductively with a pair of special glasses(spectacles) that may also remotely turn off the electro-active lenswhile the battery is being recharged. The special glasses may also beconfigured to provide vision correction while the battery is recharging.

In some embodiments, the capacitor 216 in the electro-active IOL 200 maybe charged with a special pillow that has very light gauge wires throughwhich current runs. The pillow may thus be used to charge the batteriesinside the electro-active IOL 200 at night while the patient sleeps. Anexemplary arrangement of this type is illustrated in FIG. 5 and will bediscussed in more detail below. A power conditioning circuit is used toreduce the voltage and limit the current to safe levels for low powercharging and to adjust the frequency for more efficient charging.

Alternately, the electro-active IOL may not have a capacitor 216 orbattery, but may be constantly powered conductively by an externallylocated battery, or may be constantly powered inductively by anexternally located inductively coupled power supply, or solar cell, orsolar cell coupled to a properly tuned laser, or a thermal-electricpower supply that generates electricity by dumping body heat (typically98 degrees F.) into the relatively cool ambient air (typically 70degrees F.).

FIGS. 3A and 3B display an intraocular lens system 300 having adiffractive electro-active lens element 326 and a rechargeable batteryring 324. FIG. 3A provides a front view of the diffractiveelectro-active lens element 326, said diffractive lens element can beeither electrically diffractive with circular concentric electrodes, ormechanically diffractive with etched surfaces that are activatedelectrically by controlled by index matching and mis-matching, which isconnected by power connections 322 to the rechargeable battery ring 324.Lens anchors 314 may be used to stabilize and position the diffractiveelectro-active lens element 326 in the desired location and orientation.The rechargeable battery ring 324 may be powered with a capacitorsimilar to that of intraocular lens system 200 of FIGS. 2A and 2B.Further, the rechargeable battery 324 may be shaped differently andlocated inside of or adjacent the lens anchor 314, and thus be movedaway from the optical elements.

FIG. 3B displays a side view of the intraocular lens 300. Specifically,FIG. 3B illustrates an optional base lens 352, which is similar to thebase lens 252 of the intraocular lens system 200 of FIGS. 2A and 2B.This base lens 352 may have a base or fixed optical power, or may haveno optical power and merely serve as a protective capsule or substrate.

FIGS. 4A and 4B display an intraocular lens system 400 having apixelated electro-active lens element 430 and a rechargeable batteryring 424. FIG. 4A shows a front view of the pixelated electro-activelens element 430, which is connected by power connections 422 to therechargeable battery ring 424. Lens anchors 414 may be used to stabilizeand position the diffractive electro-active lens element 430 in thedesired location and orientation. The rechargeable battery ring 424 maybe powered in the same ways as capacitor 216 from FIG. 2.

FIG. 4B displays a side view of the intraocular lens 400 showing thebase lens 452, which is similar to the base lenses of the previousembodiments.

FIG. 5 displays an external power supply 500 for use in charging theinternal power supply of IOLs according to some embodiments of theinventions. In the power supply 500, a power conditioner 532 iselectrically connected to a wall outlet 530. The power conditioner 532is connected to light gauge wire induction coils 534 inside of a pillow536 for inductively charging a capacitor or battery of a rechargeableelectro-active IOL. The power conditioner 532 may be configured toreduce the voltage and limit the current to safe levels for low powercharging and to adjust the frequency for more efficient charging. Thepower supply 500 may be configured so that the electro-active IOL may becharged while a subject rests his head on or near the pillow 536. Itwill be understood that the induction coils 534 may alternatively beplaced in a subject's bedding or in a headrest, seatback or otherlocation that can be in close proximity to a subjects head for asufficient period of time.

FIG. 6 displays an intraocular lens assembly 600 with an electro-activelens element 618, a control chip 640 and an antenna 622 for use with awireless programming unit 660. The wireless programming unit 660 isconfigured to communicate with the control chip 640 through radio waves.The radio waves are picked up by the mini antenna 642 which communicateswith the control chip 640. The control chip 640 may be remotely tunedthrough the use of these radio waves. Such tuning may include setting oradjusting the optical characteristics of the electro-active lens element618. The control chip 640 controls the electro-active lens element 618,and may have bi-directional communication with the wireless programmingunit 660. For example, the control chip 640 may be configured to alertthe wireless programming unit 660 that the battery 624 voltage is low.Alternately, programming communication with the control chip 640 may bethrough a laser (light waves), instead of through radio waves.

The electro-active lens element 618 may be connected by powerconnections 622 to a rechargeable battery ring 624 or a capacitor (notshown), and may be charged by induction coils or by piezoelectricelements as in previously described embodiments.

In some embodiments, the correction provided by the electro-active IOLmay vary depending upon the needs of the patient and the desiredresults. In some embodiments the electro-active element may only providecorrection for presbyopia. In some embodiments, the electo-active IOLmay provide remote fine tuned conventional correction. In someembodiments, the electo-active IOL may provide higher order(non-conventional) aberration corrections, by way of example only, coma,spherical aberration, trefoil, and other higher order aberrations. Insome embodiments the electro-active element may also adjust the positionof the image on the retina, by way of creating a prismatic shift of theimage electronically. When correcting for higher orders aberrations andor correcting a prismatic shift of where the image is located on theretina, the electro-active IOL may utilize a plurality of pixels. Aprismatic shift of the image is very useful in patients havingconditions, by way of example only, macula degeneration of the retina(which may include alterations in color due to disease or specificdegeneration of the macula lutea), macula holes, retinal tears, andneurological abnormalities that cause scotomas or a loss of vision inparticular segments of the visual pathway (such as blind or dark spotsin the field of vision, and blurred vision). It should be pointed outthat in each of the use embodiments above the inventive electro-activeIOL can be tuned remotely post surgery to effect the optimized effectdesired.

FIG. 7A illustrates an image of a healthy retina with a healthy fovea720 and healthy macula 710. FIG. 7B illustrates an area of the macula730 that has been damaged by “wet” macular degeneration, usually causedby bleeding from behind the retina that moves across membrane of theretina. FIG. 7C illustrates an area of the macula 740 that has beendamaged by “dry” macula degeneration, which is caused by the build-up ofdrusen on the retina in the area of the macula. By moving the image toanother location on the retina, vision can be improved for peoplesuffering from macular degeneration. An image location change of 0.25 mmto 3.00 mm may make a major improvement in one's vision in the case of adiseased or damaged macula or retina. The preferred range is 0.50 mm to2.00 mm.

FIG. 8 illustrates the effects of diabetic retinopathy on the eye.Again, by redirecting the image on the retina with a prismatic IOL, someof the visual clarity effects of this disease may be mitigated.

FIG. 9 schematically illustrates an embodiment whereby electro-activelenses with linear electrodes may be stacked to produce any combinationof vertical and horizontal displacement of an image on the retina. Thefirst lens 910 has horizontal electrodes used to produce verticalprismatic power. The second lens 920 has vertical electrodes used toproduce horizontal prismatic power. The combined lens 930 would be ableto produce a combination of vertical and horizontal image displacement.By changing the voltages on each electrode and invoking a techniqueknown as phase-wrapping, a variety of prismatic powers may be producedby such a lens. Also, multiple lenses may be stacked to produce largervalues of prismatic power. The amount of prismatic power required andthe resulting amount of image shift will vary depending upon the extentof the disease. A preferred range of image movement is between 0.1 mmand 3.0 mm, with a preferred range of 0.5 mm to 2.0 mm.

FIG. 10 illustrates an electro-active IOL in optical communication witha non-electro-active accommodative IOL. Element 1010 is anelectro-active lens that is in optical communication withnon-electro-active accommodative IOL element 1020. Note that elements1010 and 1020 are in optical series, but they are not physicallytouching each other.

While much consideration has been given to powering an electro-activelens, some electro-active materials retain their optical power in theabsence of applied electricity (such, as by way of example only, abi-stable liquid crystal). Using these type of electro-active materials,the prismatic power, an additive or subtractive power that is additiveor subtractive to the base optical power of the IOL, and/or the higherorder corrections could be set while the device is being powered, andthen would remain set after the power is removed. This may negate theneed for recharging the power source in the IOL. If the patient's visionchanges and requires new correction, he could return to the eye-careprofessional and have the IOL adjusted to a new combination of prismaticand/or higher order correction. The changes could be externally poweredremotely. For example, the external power may be RF energy similar tothe way RFID tags work today, where the reading device provides thepower to the RFID tag inductively so that the RFID can transmit it'sinformation to the RFID reader.

In same manner as the RFID tags, a tuning instrument for changing theIOL power could provide power to the controller on the electro-activeIOL, so that the controller could change the voltages on the electrodesof the IOL thus setting the localized index of refraction thatdetermines the optical properties of the electro-active IOL.

Alternately, the power may also be supplied optically by shining abright light or eye-safe laser into the eye and onto a photocell builtinto the electro-active IOL that would then provide the temporaryelectrical power needed to adjust the optical power of theelectro-active IOL. This system may also be used for communication, inaddition to supplying power.

Bi-stable twisted nematic, cholesteric and ferroelectric liquid crystalshave been used in flexible low cost LCD displays, and similar materialsmay be used in the electro-active elements of an IOL. This type ofelectrically adjusted (but otherwise non-powered) prismatic adjustment,additive or subtractive, for retinal disease tuning or higher orderaberration correction may be added to (i.e., placed in optical serieswith) any accommodative non electro-active IOL that corrects forpresbyopia. For example, electro-active elements could be placed inoptical series with non-electrical or non-powered IOLs, such as nonelectro-active IOLs that mechanically change their optical power bychanging one or more surface curvatures and/or the position of the IOLin the eye.

The addition of the electro-active lens or electro-active elements maybe accomplished in at least three ways: first, a separate electro-activeIOL may be placed in non-touching optical communication (optical series)with the non-electro-active accommodating IOL; second, an electro-activeelement can be built into one of the IOL's surfaces that does not changecontour during accommodation; and third, an electro-active element maybe placed inside of a layered non-electro-active.

For example, an electro-active element could be added in the anteriorchamber and used in optical series with an individual's functioningcrystalline lens. In this case, the crystalline lens will providenatural accommodation, and the electro-active IOL may steer the image toa healthier part of the retina, or may tune the non-electroactive IOL,or may correct for higher order aberration.

As noted above, in some embodiments, it may be a major advantage to tuneor adjust the electro-active IOL remotely. After inserting theelectro-active IOL in the eye, the optical power and the prismatic powercan be fine-tuned remotely to accomplish the optimal vision correctionto correct for conventional refractive error, or higher orderaberrations, or the precise location of the image on the retina.Further, the IOL could be tuned again at a later date to compensate forchanges in the eye over time, due to disease or aging. In cases ofcorrecting solely for conventional refractive error, the electro-activeIOL could either utilize diffraction or pixelation or both. Theelectro-active element may also perform any number of these functions incombination, as required by the patient's conditions and at thediscretion of the eye care professional.

In some embodiments, while an electro-active lens may be used to providevision correction as described in the present invention, theelectro-active lens may also be used to provide a sunglass or tintingeffect electro-actively. By using special liquid crystal layers or otherelectro-chromic materials, the electro-active IOL of the presentinvention can reduce the amount of light that hits the retina when thelight levels in the environment become uncomfortably high, or reach alevel that can be dangerous to the eye. The sunglass effect may betriggered automatically when a light sensor built into the IOL receivesan intensity of light beyond some threshold level. Alternately, thesunglass effect may be switched remotely by the user using a wirelesscommunication device couple to the control circuitry in the IOL. Thiselectro-active sunglass effect may occur in milliseconds or less, incontrast to the relatively slow reaction time of seconds (or more) forcommercial photosensitive chemical tints in conventional lenses. Onefactor in determining the reaction time of electro-active lenses is thethinness of the liquid crystal layer. For example, a 5 micron layer ofliquid crystal may react in milliseconds.

Similarly, the focusing of the electro-active elements may be performedautomatically by using a range finder, or a tilt meter (near distancewhen looking down, far distance when looking straight), or may becontrolled remotely by the user using a wireless communication device.

There are a number of electro-chromic materials. One type consists oftransparent outside layers of electrically conductive film that hasinner layers which allow the exchange of ions. When a voltage is appliedacross the outer conductive layers, ions move from one inner layer toanother, causing a change in tinting of the electro chromic material.Reversing the voltage causes the layer to become clear again. Theelectro-chromic layers can have variable light transmittance duringoperation, from about 5 to 80 percent. This type of electro chromicglazing has “memory” and does not need constant voltage after the changehas been initiated. Further, it can be tuned to block certainwavelengths, such as infrared (heat) energy.

Another electro-chromic technology is called suspended particle display(SPD). This material contains molecular particles suspended in asolution between the plates of glass. In their natural state, theparticles move randomly and collide, blocking the direct passage oflight. When switched on, the particles align rapidly and the glazingbecomes transparent. This type of switchable glazing can block up toabout 90 percent of light. Also liquid crystal has been used to provideelectro-chromic effects in sunglasses.

The systems and methods, as disclosed herein, are directed to theproblems stated above, as well as other problems that are present inconventional techniques. Any description of various products, methods,or apparatus and their attendant disadvantages described in the“Background of the Invention” is in no way intended to limit the scopeof the invention, or to imply that invention des not include some or allof the various elements of known products, methods and apparatus in oneform or another. Indeed, various embodiments of the invention may becapable of overcoming some of the disadvantages noted in the “Backgroundof the Invention,” while still retaining some or all of the variouselements of known products, methods, and apparatus in one form oranother.

What is claimed:
 1. An implantable ophthalmic device to be implanted inan eye of a subject, the implantable ophthalmic device comprising: abi-stable electro-active element to provide a first optical power in afirst state and a second optical power in a second state; a controller,operably coupled to the bi-stable electro-active element, to applyelectrical power to the bi-stable electro-active element so as to switchthe bi-stable electro-active element between the first state and thesecond state and to remove the electrical power from the bi-stableelectro-active element after switching the bi-stable electro-activeelement between the first state and the second state; and a conductivecoil, in electrical communication with the controller, to receive theelectrical power via wireless charging and to provide the electricalpower to the controller.
 2. The implantable ophthalmic device of claim1, wherein the bi-stable electro-active element comprises a bi-stableliquid crystal material to provide a refractive index change in responseto the electrical power applied by the controller.
 3. The implantableophthalmic device of claim 1, wherein the bi-stable electro-activeelement comprises a plurality of independently controllable pixels. 4.The implantable ophthalmic device of claim 1, wherein, in the secondstate, the bi-stable electro-active element is configured to provide atleast partial correction for at least one higher-order aberration of theeye.
 5. The implantable ophthalmic device of claim 1, wherein, in thesecond state, the bi-stable electro-active element is configured toprovide compensation for at least one change in the subject's vision. 6.The implantable ophthalmic device of claim 1, wherein the controller isconfigured to switch the bi-stable electro-active element between thefirst state and the second state in response to a control signalreceived via the conductive coil, from an apparatus external to the eye.7. The implantable ophthalmic device of claim 6, wherein the wirelessreceiver is configured to receive at least a portion of the electricalpower applied by the controller to the electro-active element betweenthe first state and the second state from the apparatus external to theeye.
 8. The implantable ophthalmic device of claim 6, wherein the secondoptical power is selected to compensate for a change in the subject'svision after implantation of the implantable ophthalmic device.
 9. Amethod of adjusting an implantable ophthalmic device comprising abi-stable electro-active element, implanted in an eye, that provides afirst optical power in a first state and a second optical power in asecond state, the method comprising: receiving electrical power at aconductive coil in the implantable ophthalmic device via wirelesscharging; applying the electrical power to the bi-stable electro-activeelement so as to switch the bi-stable electro-active element from thefirst state and the second state; and removing the electrical power fromthe bi-stable electro-active element after switching the bi-stableelectro-active element from the first state and the second state. 10.The method of claim 9, wherein applying the electrical power to thebi-stable electro-active element causes a change in a refractive indexof the bi-stable electro-active element.
 11. The method of claim 9,wherein applying the electrical power to the bi-stable electro-activeelement comprises selectively applying electrical power to one or moreindependently controllable pixels in the bi-stable electro-activeelement.
 12. The method of claim 9, further comprising, in the secondstate: providing at least partial correction for at least onehigher-order aberration of the eye.
 13. The method of claim 9, furthercomprising, in the second state: providing compensation for at least onechange in the subject's vision.
 14. The method of claim 9, furthercomprising: receiving a control signal via the conductive coil from anapparatus external to the eye; and applying the electrical power to thebi-stable electro-active element in response to the control signal. 15.The method of claim 14, wherein the second optical power is selected tocompensate for a change in the subject's vision after implantation ofthe implantable ophthalmic device.
 16. An implantable ophthalmic deviceto be implanted in an eye of a subject, the implantable ophthalmicdevice comprising: a static optical element to provide a fixed opticalpower; a bi-stable electro-active element, in optical communication withthe static optical element, to provide a variable optical power that atleast partially corrects for a higher-order aberration in the eye and/ora change in the subject's vision; a controller, operably coupled to theelectro-active element, to apply electrical power to the bi-stableelectro-active element in response to a control signal so as to changethe variable optical power of the bi-stable electro-active element andto remove the electrical power from the bi-stable electro-active elementafter changing the variable optical power of the bi-stableelectro-active element; and a wireless receiver, operably coupled to thecontroller, to receive the control signal and at least a portion of theelectrical power applied to the bi-stable electro-active element from atuning apparatus external to the eye.
 17. The implantable ophthalmicdevice of claim 16, wherein the bi-stable electro-active element isfurther configured to provide a change in transmittance in response tothe electrical power applied by the controller.